Ozone Generator Device

ABSTRACT

An ozone generator cartridge  60  suitable for a sterilisation, decontamination and/or sanitation device. The cartridge comprises a sealable housing  60  for providing a corona discharge, the housing containing at least one power supply unit  64  and at least one inlet  65  for connection to an oxygen or air supply, the cartridge including at least part of at least one ozone conversion cell  63  attached to and extending from an external surface of a wall of the sealed housing, the conversion cell extending into a delivery conduit  52  of a decontamination device that leads to at least one discharge outlet  16.

This invention relates to an ozone generator, particularly but notexclusively for an improved sterilisation, sanitisation and/ordecontamination device.

It is a requirement to sterilise and sanitise enclosed spaces, such askitchen areas and hospital rooms quickly and effectively, to destroypotentially harmful micro-organisms, such as bacteria and viruses,contaminating the air and surfaces there within, in an acceptabletimescale.

The biocidal activity of ozone is widely known and appreciated, and itis also known that the provision of ozone in a humid atmosphereincreases the biocidal effectiveness.

However, problems associated with the use of ozone as a biocide havebeen the relatively lengthy post-treatment process to ensure that theenvironment is safe for returning occupants, the use of potentiallyenvironmentally damaging chemicals during the process, the generalineffectiveness of the process package in sanitising the environment,and the overall lack of simplicity in quickly setting up and using theapparatus.

The Applicant's previous application EP 1500404 (Steritrox Limited) andunpublished pending GB Application No.s 0904262.3, 0904264.9, 0904266.4,0904269.8 and 0904272.2 relate to their methods for decontamination ofan environment using the beneficial effect of ozone in a humidatmosphere. Whilst these processes are efficient at providing a sterileenvironment, the operation of such processes in practice require a largenumber of internal components to be provided within a packaged product.This can lead to an undesirably large and heavy end product with limitedaccess to the internal parts. It is desirable to provide an apparatusthat allows for a compact design of machine whilst enabling easyreplacement of internal components, such as the ozone generator.

The present invention seeks to provide a solution to this problem, inparticular to provide a sterilisation, sanitisation and/ordecontamination device that provides a more compact product withincreased accessibility to internal components.

According to a first aspect of the present invention, there is providedan ozone generator cartridge suitable for a sterilisation,decontamination and/or sanitation device, the cartridge comprising asealable housing for providing a corona discharge, the housingcontaining at least one power supply unit and at least one inlet forconnection to an oxygen or air supply, the cartridge including at leastpart of at least one ozone conversion cell attached to and extendingfrom an external surface of a wall of the sealed housing.

The parts of the ozone conversion cell attached to and extending fromthe external surface of a wall of the sealed housing preferably comprisethose components of the cell that generate heat during the production ofozone, more preferably, one or more electrodes, dielectric, fins and/orozone outlets. Preferably, each ozone conversion cell is in the form ofa block extending from the external surface of the wall of the sealedhousing. Preferably, the components of the ozone generator that must beisolated from the ozone, in particular the power supply and electricsthat energise the conversion cell, are provided within the housing,preferably being attached to the internal surface of the wall from whichthe ozone conversion cell extends.

Preferably, the housing is in the general form of an elongated boxhaving two opposing long walls and two opposing short walls sealed byend caps. Preferably, the ozone conversion cell extends substantiallyorthogonally from the wall of the housing.

More preferably, the housing making up the ozone generator cartridgecomprises a main body with a cover. The main body preferably comprises aflat main panel or mounting plate with one long side wall and two shortside walls extending substantially orthogonally from the panel or plate.The cover preferably comprises a generally L-shaped panel, the shortlimb of the cover making up the opposing long side wall in the assembledhousing. The components of the ozone generator that must not be exposedto high levels of ozone are fixed to the inner surface of the main panelor mounting plate which is sealable within the housing by means of thecover. The at least part of an ozone conversion cell extends from theexternal surface of the main panel or mounting plate.

The components may be made of any suitable material that is inert toozone. Preferably, an aluminium oxide coating is applied to thecomponents.

One or more air movement devices, such as fans, may be provided withinthe housing to aid cooling of the cartridge and prevent the build up ofhot spots within the housing.

The ozone generator cartridge is a stand-alone component which may befitted to a sterilisation, decontamination and/or sanitation device. Tothis end, a second aspect of the present invention provides asterilisation, decontamination and/or sanitation device comprising atleast a humidifier unit, an ozone generator, a delivery conduit and adischarge outlet, the ozone generator comprising a sealable housing forproviding a corona discharge, the housing containing at least one powersupply unit and at least one inlet for connection to an oxygen or airsupply, the generator including at least part of at least one ozoneconversion cell attached to and extending from an external surface ofthe sealed housing into the delivery conduit leading to the at least onedischarge outlet.

Preferably, the device further includes a controller for controlling thehumidifier and ozone generator units.

More preferably, the ozone generator is detachable from the deliveryconduit that leads to the discharge outlet, thereby enabling its easyreplacement. Preferably, a fan is provided at the base of the deliveryconduit remote from the discharge outlet for moving air and ozonethrough the conduit and out of the discharge outlet. This provides muchneeded cooling of the components of the ozone conversion cell and, byconvection through the surface of the sealed housing, also cools theinternal components that are mounted on the internal surface of thesurface from which the ozone conversion cell extends. Additionally, thissingle fan provides forced air for feeding ozone rich air into thehumidifier unit and provides increased air circulation within the targetarea by drawing air in at the base of the device for discharge at thetop of the device.

More preferably, the external surface of the ozone generator cartridgesupporting the ozone conversion cell comprises a wall of the deliveryconduit. Preferably, the conversion cell extends transversely across thecavity of the conduit. In a preferred embodiment, the delivery conduitis in the general shape of a rectangle having only three solid sides.The fourth side is provided by the ozone generator cartridge, moreparticularly the main panel or mounting plate of the body of thehousing.

The sides of the delivery conduit may converge towards each other asthey approach the discharge outlet. Preferably, ozone generated by theozone generator unit is discharged through the discharge outletcomprising at least two at least partially converging plates. It ispreferable for the plates to be in the form of discs.

Preferably, the humidifier comprises a water reservoir and at least onedischarge nozzle for releasing water droplets as a fine spray.Preferably, the at least one discharge nozzle is attached to the upperplate of the discharge outlet, remote from the lower plate. In thismanner, the water droplets are supported by the airstream dischargedfrom the discharge outlet.

Preferably, the humidifier, water reservoir, ozone generator, controllerand conduit are provided within a casing or enclosure with the dischargeoutlet extending from the intended upper surface of the casing. It is tobe appreciated that the casing or enclosure may include additionalcomponents for optimization of the operation of the device, such as ahydrocarbon discharge unit and/or a UV catalyst, appropriate sensors, afan, an oxygen supply and/or a water reservoir. A framework may beprovided for supporting the components within the enclosure.

The invention will now be more specifically described, by way of exampleonly, with reference to the accompanying drawings, in which:

FIG. 1 is plan top elevation external view of a sterilisation anddecontamination device according to one embodiment of the presentinvention;

FIG. 2 is a side elevation external view of the device shown in FIG. 1;

FIG. 3 is a rear elevation external view of the device shown in FIG. 1;

FIG. 4 is an exploded perspective view of certain internal components ofthe device, specifically showing the ozone generator cartridge accordingto one embodiment of the present invention, together with the dischargeoutlet assembly;

FIG. 5 is a perspective view of the components of FIG. 4, shownassembled together; and

FIG. 6 illustrates the internal components of the sterilisation anddecontamination device shown in FIG. 1.

Referring now to the accompanying drawings, there is shown an example ofa sterilisation and decontamination device 1 according to one embodimentof the present invention. The apparatus comprises a portable enclosure 1having a main body 10 and a detachable control panel 12. In theembodiment shown, the control panel is in the preferred form of adetachable lectern but it is to be appreciated that the invention is notlimited thereto and that the control panel may be provided elsewhere onthe enclosure or remote thereto.

The main body 10 has wheels 14 and handles 15 and houses the componentsof the device (see, in particular, FIG. 6) that are required forcarrying out the decontamination process, in particular a humidifierunit and an ozone generator unit. The main body may also include acatalyst assembly 40 and/or a hydrocarbon generator unit for supplying ahydrocarbon containing a carbon-carbon double bond and/or for aidingremoval of by-products. A discharge outlet assembly 16 extends from thetop of the main body to discharge the required substances into theatmosphere and a microprocessor is provided within the unit forcontrolling discharge from the outlet assembly.

The humidifier unit generally includes a humidifier, a humidistatsensor, a temperature sensor and a water reservoir 90. The humidifierreleases water droplets from the discharge outlet assembly 16. The waterdroplets have a diameter of less than 5 microns, preferably 2-3 microns,to enhance the rate of evaporation into the atmosphere. The ozonegenerator unit includes an ozone generator 60, an ozone detector sensor,and an oxygen supply 66 for supplying oxygen to the ozone generator. Allthese components are housed within or on the housing forming the mainbody 10—see FIG. 6. A suitable framework may be provided for supportingthe various components.

It is to be appreciated that the large number of internal componentshoused within the packaging of the machine may lead to a bulky and heavydevice, making the device less user friendly. Furthermore, thearrangement of the components in a limited space makes maintenance andreplacement of individual components more difficult. The presentinvention provides a removable ozone generator cartridge 60 that allowsfor fewer parts, reduces the overall space taken up by the componentsand also allows for easier maintenance and replacement of the ozonegenerator.

In particular, FIGS. 4 and 5 of the accompanying drawings illustrate anozone generator cartridge according to one embodiment of the presentinvention. The ozone generator cartridge 60 comprises a housingincluding a slimline body 62 with a cover 61. The body comprises a flatmounting plate 62 a with one long side wall 62 b and two short sidewalls 62 c extending substantially orthogonally from the plate. Thecover 61 comprises a generally L-shaped panel, the short limb 61 a ofthe cover making up the opposing long side wall in the assembledhousing. The intended inner surface of the mounting plate of the bodyhas the components of the ozone generator that must not be exposed tohigh levels of ozone attached thereto or formed integrally therewith,particularly the high tension power supply units (HT PSUs) 64 andprinted circuit boards (PCBs). These components are sealable within thehousing by means of the cover 61. Suitable fixing means (not shown) areprovided to secure the cover to the body of the cartridge. The housingalso has at least one inlet 65 for the introduction of oxygen (or air)for the production of ozone and the connection of a power supplythereto. Extending from the external surface of the mounting plate 62 a,away from the interior of the housing, are components of the ozonegenerator that do not have to be isolated from the path of the ozone,specifically the ozone conversion cell block 63 which in the illustratedexample comprises electrodes, dielectric and fins for maintaining theelectrical discharge for the production of the ozone, together with anozone discharge outlet (not shown). The cartridge is also provided withappropriate conduits for delivering the oxygen and ozone through, aroundand out of the generator.

The complete ozone generator cartridge forms the fourth side of adelivery or launch tube 52 within the air decontamination device (seeFIGS. 5 and 6). The ozone conversion cell blocks 63 extend transverselyacross the tube 52 with the other components of the ozone generatorbeing sealed within the housing but positioned against the wall of thelaunch tube 52. A common fan 50 is provided at the base of a launch tube52, being supported by a bracket 51 attached to the base of the tube.The upper end of the tube leads to the discharge outlet 16 whichcomprises a 360 degree high volume air outlet. The discharge outletassembly comprises a pair of converging plates 72, 74, preferably in theform of discs, between which the air containing the ozone, isdischarged. Water discharge nozzles 80 are attached to the upper surfaceof the top plate 74 to introduce filtered water to a specific formulaproviding the necessary sterilisation and conductivity to provideeffectiveness of humidification application and minimal systemmaintenance to the atmosphere. One or more water reservoirs 90 deliverwater to a compressor (not shown) which in turn delivers high pressurewater (at least 50 Bar) to the discharge nozzles. A cover or cap 82 isfitted over the water discharge nozzles, the cover being contoured suchas to direct any water to a drainage collection point and a mesh orgauze 78 is provided between the converging plates to prevent theingress of any foreign objects.

The conduits (not shown) that determine the flow of oxygen and ozone in,through and out of the ozone generator cartridge are preferably arrangedto release the bulk of the ozone towards the top of the ozone generator,above the conversion cells 63. The arrangement of the ozone generator,delivery tube and discharge outlet assembly is such that a single fancan be used not only to create the required airflow but also to providea cooling airflow for the ozone generators and aid mixing of the ozonewithin the delivery tube. This is important as 85% to 95% of theelectrical energy supplied to a corona discharge ozone generatorproduces heat which must be removed. Thus, the ability to cool thecomponents of the device whilst simultaneously moving the air throughand out of the device has clear financial and weight benefits. Themounting plate of the ozone generator cartridge also acts as a radiatorto effect cooling of the internal components of the housing that aremounted on the internal surface of the mounting plate.

If the decontamination device 1 is to include a hydrocarbon dischargeunit this too is housed within the main body 10 of the machine andincludes a hydrocarbon supply in the form of a tank or containercontaining the hydrocarbon having a carbon-carbon double bond, such as asecondary olefin, cis or trans, including cyclic olefins together withmeans to discharge the hydrocarbon through the discharge outlet.

Access to the interior of the main body 10 of the machine is provided bya removable, preferably lockable, side panel or lid. The main body 10also includes part of a control unit in the form of a microprocessorwhich controls the apparatus 1 and may be preset with at least onesterilisation and decontamination routine. The control unit includes acontroller and a user interface which is located on the detachablelectern 12 by which a user can wirelessly input commands to the mainbody to remotely control operation of the device.

The apparatus 1 may include an on-board battery and/or may beconnectable to a mains power supply. Preferably, the main body 10 may beconnected to a mains supply and the lectern 12 is battery-operated,being charged by power from the main body when the lectern is dockedtherein.

The apparatus 1 will also typically include other safety features, suchas safety sensors, and software routines to prevent start-up or initiateshut-down in the event of a system failure.

In use, the whole device 1 comprising the main body 10 connected to thelectern 12 is wheeled into an area which is to be sterilised and/ordecontaminated. The unit is correctly positioned and then the lectern isdetached from the main body by lifting and tilting the lectern onto itswheels. The lectern is then wheeled out of the room and positionedacross a door or other opening that allows access to the area beingdecontaminated. This acts as a warning and bollard to prevent any personentering the area. Furthermore, the lectern enables operation of thecomponents within the main body to be controlled remotely from outsideof the room by means of the user interface connected wirelessly to themicroprocessor controlling the main body within the room. Duringoperation of the device, the display unit on the top part of the lecternmay display a visible warning to inform personnel that thedecontamination process is being carried out and that the area should beleft unoccupied. The lectern may also provide a visible or audio messagewhen decontamination is complete, informing the user that the room maybe re-occupied. Other appropriate data and information may be stored foraccess by the user.

During operation of the device, the area is sealed and the control unitlocated on the main body undertakes appropriate initial safety checkssuch as checking the relative humidity. If the safety check is notpassed, the apparatus 1 does not operate and outputs a suitableindication using warning lights which may be on one or both of the mainbody and the lectern. During operation of the process, safety checks aremade continuously, and in the event of a system failure, the systemdefaults to a safe mode.

The controller continues to monitor the conditions provided by thedevice and once a calculated relative humidity level is reached, thecontroller activates the ozone generator and ozone is generated.Alternatively, the ozone may be generated prior to or simultaneouslywith the production of the required relative humidity levels. Thegenerated ozone is fed into the discharging humidified airstream thatpasses through the discharge outlet 16. The controller provides asuitable indication that the ozone generator is operating, and monitorsthe ambient ozone levels through the ozone detector sensor.

Both the ozone and water vapour concentrations to be detected can bealtered by means of the user interface. However a typical setting is 25ppm v/v of ozone and 13.6 tom Once the preset ozone and water vapourlevels have been detected within the allotted interval, the controllerenters a timing phase, known as the “dwell time”.

The dwell time can also be altered using the remote user interface, forexample, to one hour, and will depend on the degree and type ofdecontamination/sanitisation to be provided. For instance, contaminationby spores or moulds, such as clostridium difficile, generally require alonger dwell time than contamination by bacteria, such as listeria andmethicillin resistant staphylococcus aureus (MRSA).

During the dwell time, the ozone concentration and relative humidity arecontinuously monitored. If the ozone level falls below a predeterminedthreshold, the ozone discharge unit is reactivated to replenish theozone levels. If the humidity falls below the calculated value, thehumidifier unit is reactivated to restore the water vapour level.

Again, during the reactivation period, should either the ozoneconcentration or the relative humidity fail to reach the above-mentionedpredetermined minima within a set time interval, for example 10 minutes,the controller aborts the sterilisation and decontamination routine andoutputs a suitable indication.

After the dwell time has elapsed, the controller shuts down the varioussupply units and, if a hydrocarbon is to be supplied, operates ahydrocarbon discharge unit to discharge the hydrocarbon into the ambientenvironment. The hydrocarbon preferentially reacts with the residualozone to accelerate the breakdown of the ozone, thereby offering fasteruser re-entry to the treated area.

When an ozone detector sensor detects that the ozone concentrationlevels are less than a predetermined value, for example 0.2 ppm or less,the controller shuts off supply of the hydrocarbon and outputs anindication that the sterilisation and decontamination routine iscomplete. Again this is visible on the user display of the lectern and,optionally, the main body of the machine. The ozone level of 0.2 ppm,depending on the size of the area being sterilised and decontaminated,is usually achieved in less than 3 to 4 minutes.

If the ozone detector sensor fails to indicate that the predeterminedsafe level of ozone has been reached within a predetermined timeinterval following introduction of the hydrocarbon, for example within10 minutes, the controller outputs an indication warning of potentiallyhazardous ozone levels in the room. The controller may be programmed toallow a time interval to elapse in excess of the standard half-life ofozone before announcing that the room may be re-occupied.

The above-described apparatus utilises a method of producing anartificially high level of non-condensing humidity, and generatingin-situ a high concentration of ozone. The materials of the apparatusare resistant to the corrosive effects of ozone and high humidity, andthe solvent effects of the hydrocarbon.

It is thus possible to provide a device for decontamination of an areawhich is fast and effective, discrete and portable. The method mayprovide better than 99.99% effective sterilisation and/ordecontamination of an area without an impact on the environment fromharmful by-products. Rapid re-use of a contaminated area can thus berealised. The above-described method has proven to be lethal to a widevariety of pathogens, including bacteria such as Methicillin ResistantStaphylococcus Aureus (MRSA). The particular arrangement of thecomponents of the ozone generator enables the ozone cartridge to berepaired and/or replaced easily with the components taking up less spacewithin the machine due to the arrangement of certain components outsidethe sealed housing. This has the additional benefit of providing thesecomponents within the flow path of air circulated by a single fansituated at the base of the delivery tube. Again, this provides clearfinancial savings, as well as enabling the machine to more compact andlightweight. The internal components of the ozone cartridge, whilstbeing isolated from high ozone concentrations, are also cooled by theflow of air that contacts the surface of the wall of the cartridge thatcompletes the delivery tube.

The device according to the present invention is able to facilitate bothatmospheric and surface decontamination of a hospital room within justone hour. The device is such that is can be wheeled into a vacated roomand be activated from outside the room by janitorial staff with minimaltraining using a simple touch screen control pad. The entire processrequires minimal supervision while the intelligent control systemconstantly monitors room conditions and alerts staff whendecontamination is complete or a problem is encountered.

The embodiments described above are given by way of examples only, andother modifications will be apparent to persons skilled in the artwithout departing from the scope of the invention as defined by theappended claims.

1. An ozone generator cartridge comprising a sealable housing forproviding a corona discharge, the housing containing at least one powersupply unit and at least one inlet for connection to an oxygen or airsupply, the cartridge including at least part of at least one ozoneconversion cell attached to and extending from an external surface of awall of the housing.
 2. An ozone generator cartridge as claimed in claim1 wherein the ozone conversion cell attached to and extending from anexternal surface of the wall of the housing comprises at least one pairof electrodes and a dielectric.
 3. An ozone generator cartridge asclaimed in claim 1 wherein the at least one power supply unit of theozone generator is attached to the internal surface of the wall to whichthe ozone conversion cell is attached externally.
 4. An ozone generatorcartridge as claimed in claim 1 wherein at least one printed circuitboard is attached to or formed integrally with the internal surface ofthe wall to which the ozone conversion cell is attached externally. 5.An ozone generator cartridge as claimed in claim 1 wherein the ozoneconversion cell extends substantially orthogonally from the wall of thehousing.
 6. An ozone generator cartridge as claimed in claim 1 whereinthe housing comprises a main body with a cover.
 7. An ozone generatorcartridge as claimed in claim 6 wherein the main body comprises asubstantially flat main panel or mounting plate with one long side walland two short side walls extending substantially orthogonally from thepanel and the cover comprises a generally L-shaped panel, the short limbof the cover making up the opposing long side wall in the assembledhousing.
 8. An ozone generator cartridge as claimed in claim 6 whereinthe main body comprises a substantially flat main panel or mountingplate with one long side wall and two short side walls extendingsubstantially orthogonally from the panel and the cover comprises agenerally L-shaped panel, the short limb of the cover making up theopposing long side wall in the assembled housing and wherein componentsof the ozone generator that must not be exposed to high levels of ozoneare fixed to the inner surface of the main panel or mounting plate whichare sealable within the housing by means of the cover, with the ozoneconversion cell extending from the external surface of the main panel ormounting plate.
 9. A sterilisation, decontamination and/or sanitationdevice comprising at least a humidifier unit, an ozone generator, adelivery conduit and a discharge outlet, the ozone generator comprisinga sealable housing for providing a corona discharge, the housingcontaining at least one power supply unit and at least one inlet forconnection to an oxygen or air supply, the generator including at leastpart of at least one ozone conversion cell attached to and extendingfrom an external surface of the sealed housing into the delivery conduitthat leads to the least one discharge outlet.
 10. A device as claimed inclaim 9 wherein the ozone generator is detachable from the deliveryconduit to enable its replacement.
 11. A device as claimed in claim 9wherein the external surface of the ozone generator supporting the ozoneconversion cell comprises a wall of the delivery conduit.
 12. A deviceas claimed in claim 11 wherein the delivery conduit is in the generalshape of a rectangle having three solid sides, the fourth side beingprovided by the ozone generator.
 13. A device as claimed in claim 9wherein a fan is provided at the base of the delivery conduit remotefrom the discharge outlet for moving air and ozone through the conduitand out of the discharge outlet.
 14. A device as claimed in claim 9wherein ozone generated by the ozone generator unit is dischargedthrough the discharge outlet comprising at least two at least partiallyconverging plates.
 15. A device as claimed in claim 9 wherein thehumidifier, ozone generator, and conduit are provided within a housingwith the discharge outlet extending from the intended upper surface ofthe housing. 16-17. (canceled)